创建数据库的一张表 表名为User

 

我们新建一个普通的maven项目

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <project xmlns="http://maven.apache.org/POM/4.0.0"
 3          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 4          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 5     <modelVersion>4.0.0</modelVersion>
 6 
 7     <groupId>org.west</groupId>
 8     <artifactId>MybatisLove</artifactId>
 9     <version>1.0-SNAPSHOT</version>
10 
11     <dependencies>
12         <!--单元测试-->
13         <dependency>
14             <groupId>junit</groupId>
15             <artifactId>junit</artifactId>
16             <version>4.11</version>
17         </dependency>
18 
19         <!--mybatis的包-->
20         <dependency>
21             <groupId>org.mybatis</groupId>
22             <artifactId>mybatis</artifactId>
23             <version>3.5.1</version>
24         </dependency>
25 
26         <!--连接数据库的驱动包-->
27         <dependency>
28             <groupId>mysql</groupId>
29             <artifactId>mysql-connector-java</artifactId>
30             <version>5.1.47</version>
31         </dependency>
32 
33         <!--LOG4J日志包-->
34         <dependency>
35             <groupId>log4j</groupId>
36             <artifactId>log4j</artifactId>
37             <version>1.2.17</version>
38         </dependency>
39 
40     </dependencies>
41 
42     <build>
43         <!--希望maven在导出项目的时,能够将我们的配置及资源导出-->
44         <resources>
45             <resource>
46                 <directory>src/main/java</directory>
47                 <includes>
48                     <include>**/*.properties</include>
49                     <include>**/*.xml</include>
50                 </includes>
51                 <filtering>false</filtering>
52             </resource>
53             <resource>
54                 <directory>src/main/resources</directory>
55                 <includes>
56                     <include>**/*.properties</include>
57                     <include>**/*.xml</include>
58                 </includes>
59                 <filtering>false</filtering>
60             </resource>
61         </resources>
62     </build>
63 
64 
65 </project>

然后在建一个实体类pojo

 1 package org.west.pojo;
 2 
 3 public class User {
 4     private int id;
 5     private String name;
 6     private String pwd;
 7 
 8     public User() {
 9     }
10 
11     public int getId() {
12         return id;
13     }
14 
15     public void setId(int id) {
16         this.id = id;
17     }
18 
19     public String getName() {
20         return name;
21     }
22 
23     public void setName(String name) {
24         this.name = name;
25     }
26 
27     public String getPwd() {
28         return pwd;
29     }
30 
31     public void setPwd(String pwd) {
32         this.pwd = pwd;
33     }
34 
35     @Override
36     public String toString() {
37         return "User{" +
38                 "id=" + id +
39                 ", name='" + name + '\'' +
40                 ", pwd='" + pwd + '\'' +
41                 '}';
42     }
43 }

编写一个工具类

 1 package org.west.utils;
 2 
 3 import org.apache.ibatis.io.Resources;
 4 import org.apache.ibatis.session.SqlSession;
 5 import org.apache.ibatis.session.SqlSessionFactory;
 6 import org.apache.ibatis.session.SqlSessionFactoryBuilder;
 7 
 8 import java.io.IOException;
 9 import java.io.InputStream;
10 
11 public class MybatisUtils {
12     public static SqlSessionFactory sqlSessionFactory;
13 
14     static {
15 
16         try {
17             String resource="mybatis-config.xml";
18             InputStream inputStream = Resources.getResourceAsStream(resource);
19             sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
20         } catch (IOException e) {
21             e.printStackTrace();
22         }
23     }
24     public static SqlSessionFactory getSqlSessionFactory(){
25 
26         return sqlSessionFactory;
27     }
28     public static SqlSession getSqlSession(){
29 
30         return sqlSessionFactory.openSession(true);
31 
32     }
33 
34 }

编写核心配置文件xml

 1 <?xml version="1.0" encoding="UTF-8" ?>
 2 <!DOCTYPE configuration
 3         PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
 4         "http://mybatis.org/dtd/mybatis-3-config.dtd">
 5 <configuration>
 6     <!--数据配置文件-->
 7     <properties resource="db.properties"/>
 8 
 9     <!--日志-->
10     <settings>
11         <setting name="logImpl" value="LOG4J"/>
12     </settings>
13 
14     <!--别名优化-->
15     <typeAliases>
16         <package name="org.westos.pojo"/>
17     </typeAliases>
18 
19 
20     <environments default="development">
21         <environment id="development">
22             <transactionManager type="JDBC"/>
23             <dataSource type="POOLED">
24                 <property name="driver" value="${driver}"/>
25                 <property name="url" value="${url}"/>
26                 <property name="username" value="${username}"/>
27                 <property name="password" value="${password}"/>
28             </dataSource>
29         </environment>
30     </environments>
31 <mappers>
32     <mapper class="org.west.dao.UserDao"/>
33 </mappers>
34 
35 </configuration>

编写接口 使用注解

package org.west.dao;

import org.apache.ibatis.annotations.Select;
import org.west.pojo.User;

import java.util.List;

public interface UserDao {
@Select("select *from user")
List<User> getUserList();

}

编写测试类

package org.west;

import org.apache.ibatis.session.SqlSession;
import org.junit.Test;
import org.west.dao.UserDao;
import org.west.pojo.User;
import org.west.utils.MybatisUtils;

import java.util.List;

public class TestDao {
    @Test
    public void test(){

        SqlSession sqlSession = MybatisUtils.getSqlSession();
        UserDao mapper = sqlSession.getMapper(UserDao.class);
        List<User> userList = mapper.getUserList();
        for (User user : userList) {
            System.out.println(user);
        }

    }
}

项目整体目录

运行结果: